You are working as the resus registrar and have been asked to assess a patient for sedation for cardioversion.
He is a 37 year old man who has a background history of dysrhythmia. He has had palpitations for the last 8 hours and has had no resolution after taking his PRN Sotolol.
His observations are BP 128/92, RR18, Sats 99% on air, T35.7 BSL 6.5.
His K and Mg are normal and has had recent normal TFTs.
ECG is as follows:
Questions:
- Interpret his ECG
- What other details do you want to know from your airway assessment?
- What risks will you make him aware of as you take his consent for DCCV?
Interpretation:
- Rate: 126 (post B blocker)
- Rhythm: Narrow complex tachycardia with evidence of AV block
- Regular atrial rate seen most clearly in inferolateral leads (note how they can hide in the QRS complexes) – rate around 300
- Axis: Normal 0-90
- Morphology: nil of note
- Intervals: QRS 100 QTC 450
- Summary: DDx Atrial Tachycardia vs Atrial flutter with 2: 1 block
Airway assessment:
- History: starvation status, meds inc anticoagulants, allergies, previous anaesthetic problems (this man had had laryngospasm post tonsillectomy) Etoh or illicit drug intake
- Examination: weight, teeth, neck mobility, mouth opening, thyromental distance, Mallonpatti scoring
Consent:
- Benefits: reduce long term risk of stroke and tachycardia induced myopathy
- Alternative treatment: trial adenosine
- Risks:
- Of cardioversion – failure (20%), stroke (<1%), rhythm degeneration.
- Defibrillation – myalgias, burns or reactions to electrodes, repeated shocks
- Anaesthetic – airway management, aspiration, hypoxia, hypotension, conversion to GA.
Further reading: classification of flutters and the basics